1. Field of the Invention
The present invention relates to a method of fabricating a digit line and a cell contact.
2. Description of the Prior Art
A dynamic random access memory (DRAM) device comprises an arrangement of individual memory cells. Each memory cell includes a capacitor capable of holding data as an electrical charge and an access transistor for accessing the charge stored on the capacitor. The data is transmitted on signal lines, referred to as bit lines, or digit lines. The digit line is coupled directly to a source doping region of an access transistor for a particular memory cell. A cell contact couples to a drain doping region of the access transistor for transfer the data from the digit line to the capacitor. The digit line and the cell contact are usually fabricated as metal, silicide or polysilicon.
As the market pressure to increase the memory cell density is continuously growing. A unique fabrication process is needed to reduce the size of the memory cells, and provide an easier approach to form digit lines and cell contacts.